Note: Descriptions are shown in the official language in which they were submitted.
HIGH BULK DENSITY CARBONATE-ZEOLITE BUILT
HEAVY DUTY NONIONIC LRUNDRY DETERGENT
This invention relates to built synthetic organic
detergent compositions useful for the heavy duty laundering
of ~ashable clothing and other textile items, and to a method
for the manufacture thereof. More particularly, it relates
to an improved non-phosphate synthetic organic detergent
composition based on nonionic synthetic organic detergent
synthetic; ~eolite builder, sodium carbonate and hydrous sodium
silicate, which is free flowing and of high bulk density and
deposits little residue on washed materials.
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Although synthetic organic detergent compositions
- have long been based on mixtures of synthetic organic detergent,
usually anionic detergent, such as a linear alkyl benzene
sulfonate, and builder salt, usually pentasodium tripolyphosphate,
because of anti-eutrophication laws and governmental regulations
the phosphate content of heavy duty detergent compositions has
been limited and in some instances it has been considered
desirable to produce low phosphate or phosphate-free detergent
compositions. Water insoluble builders, such as bentonite ;
and natural zeolites had previously been employed in soap
and synthetic organic detergent compositions for their
desirable effect in removing hardness ions, such as calcium
and magnesium ions, from wash waters. More recently) with
the availability of synthetic zeolites of improved hardness
ion-counteracting properties, such zeolites have been included
in detergent products to remove such ions and to improve
detergency of the synthetic organic ~usually anionic)
~` detergent present. Such products may be of low phosphate
content or free of phosphate and may be chemically mactive
and non-nutritive, hence not contributing to algae growth
and eutrophication of inland waters. Although the detergent
compositions may be advantageous in those respects, it has
been noted that materials washed with them can have objectionable 1 ;
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quantities of residue deposited on them. This is most
objectionable when the light-colored residue is readily
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apparent on a dark material. Accordingly, efforts have been
made to reduce the depositing of such residue while still
producing a satisfactory detergent. In United States patent
, 3,985,669 it is reported that less residue is present in such
detergent compositions when the quantity of silicate is main-
tained low. However, with comparatively large quantities of
synthetic zeolite, especially that of a type prone to deposit
on such substrates, objectionable deposits can still result.
Also, reducing the proportion of silicate present may diminish
the anti-corrosive effect of such normally desirable component
- of synthetic detergent compositions. Accordingly, other
~` ways of preventing such deposits have been the subjects of
research projects.
Recently it has been considered desirable by the
assignee of the present invention to produce free flowing
and comparatively high bulk-density particulate heavy duty
laundry detergents so that relatively small quantities of
these can be employed and will effectively clean in normal
heavy duty laundering operations. It has been found that a
~0 combination of nonionic detergent, synthetic zeolite, sodium
carbonate and sodium bicarbonate can be made into a free
flowing, high bulk density, phosphate-free product. For
example, a mixed salt, such as Wegscheider's
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19
salt, may be tumbled with nonionic detergent and the product may be
coated with synthetic zeolite powder. While the products
made are useful detergents of desired high bulk density, they
may be of somewhat different appearance from that of conventional
detergents normally purchased by the householder and therefore
they might not be as readily accepted in the marketplace.
Also, products which are spray dried or are made substantially
from spray dried base beads, which are produced from homogeneous
crutcher mixes, tend to be more uniform in composition and
when materials blended with them constitute only minor
proportions of the final product generally the post-spraying
and mixing processes utilized in their manufacture do not
require as strict control to ensure obtaining production of
desirably homogeneous and free flowing products, compared to
the method described above in this paragraph for example. Addi-
tionally, most detergent manufacturers are equipped with spray
drying facilities and continuation of the use of such is often
economically desirable. The present methods allow production of a
free flowing, high bulk density, phosphate-free (or low phosphate)
heavy duty laundry detergent of non-sifting characteristics, good
washing properties, low residue deposition characteristics and
attractive appearance to be readily carried out by methods
utili2ing for a substantial part equipment already on hand`and with
whicll operators are familiar.
In accordance with the present invention a method of
manufacturing a free flowing, phosphate-free, particulate heavY
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duty laundry detergent of a bulk density greater than 0.6 g./ml. which comprises spray drying an aqueous mixture of ion
exchanging zeolite, sodium carbonate and water to a moisture
content in the range of about 2 to 16% so that the proportion
of zeolite of sodium carbonate in the spray dried beads pro-
duced is in the range of l:o.l-1.5 and mixing with said beads
from 0.1 to 0.3 part of hydrous sodium silicate in particulate
form and 0.2 to 1.0 part of nonionic detergent in liquid form
per part of zeolite so that such detergent is absorbed into
the beads. The invention is also in the product resulting
and other such products which comprise beads of ion exchanging
zeolite and sodium carbonate in the proportion of 1:0.1-1.5,
having mixed with them from 0.1 to 0.3 part of hydrous sodium
silicate in particulate form and 0.2 to 1.0 part of nonionic
detergent per part of zeolite. The nonionic detergent may be
absorbed into the spray dried beads and may hold the hydrous
silicate in or on the beads. Proportions given are on
anhydrous bases.
Nonionic detergents are listed at length in
McCutcheon's Detergents and Emulsifiers, 1973 Annual and in
Surface Active Agents, Vol. II, by Schwartz, Perry and Berch
(Interscience Publishers, 1958). Such detergents may be
liquid, pasty or waxy solids at room temperature (20C) and
are usually either sufficiently water soluble to dissolve
promptly in water or will quickly melt at the temperature of
the wash water, as when that temperature is a~out 30 or 4QC.
While the nonionic detergent employed will normally be one
which is either liquid or pasty at room temperature, often
preference will be given to normally liquid products because
these readily penetrate into the interiors of the base particles
surprisingly leaving little or no material at the surfaces
thereof, thus avoiding any tackiness due to presence of the
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nonionic detergent at the particle surfaces. The use of the
normally liquid nonionic detergents allows room temperature
application of the nonionic material to the base particles and
avoids problems encountered due to any premature solidification
of the nonionic or due to the presence of a pasty material near
the surfaces thereof, which can be the result of undesired
quick cooling of such nonionic detergen-t before it has satis-
factorily penetrated into the interior of the base particle.
Thus, although it would have been expected that one would
prefer to
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employ a solid nonionic detergent or at least one which is normally pasty or
semi-solid because it would be considered that such would be less liable to
make a tacky product of poor flow properties and susceptibility toward lump-
ing or setting on storage than liquid nonionic detergents, this is not the
case. If the base beads are kept warm enough and the nonionic detergent is
applied in liquid state, as may be effected when normally solid or pasty non-
ionic detergent lS heated sufficiently, the product resulting, providing that
penetration into the base bead interior is sufficient, will be as good as the
` preferred liquid nonionic detergent-base bead compositions with respect to
the flow and non-lumping properties but even in such case the liquid nonionic
detergent is more amenable to being dispersed readily in aqueous media and
therefore is more quickly effective in wash water. Generally, if a normally
pasty, semi-solid or solid nonionic detergent is employed, when it is applied
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to the base beads it will be in the liquid state and usually will be at a
temperature below 50 or 60C, always below 70C and preferably below 45C.
~or example, when a normally solid nonionic detergent such as Alfonic 1618-65
is employed, it will be heated so as to be a liquid upon application but when
Neodol 25-6.5 or 25-7 is used heating will be unnecessary, providing that
room temperature application, such as at 25C, is efected.
" ~0 Typical useful nonionic detergents are the poly- (lower alkenoxy)
derivatives that are usually prepared by the condensation of lower ~2 to 4
.`~ carbon atoms) alkylene oxide, e.g., ethylene oxide, propylene oxide ~with
cnough ethylene oxide to make a water soluble product), with a compound hav-
ing a hydrophobic hydrocarbon chain and containing one or more active hydro-
~en atoms, such as higher alkyl phenols, higher fatty acids, higher fatty
mercaptans, higher fatty amines and higher fatty polyols and alcohols, e.g.,
fatty alcohols having 8 to 20 or 10 or 12 to 18 carbon atoms in an alkyl
chain and alkoxylated with an average of about 3 to 30, preferably 5 to 20
and more preferably 5 to 12 lower alkylene oxide, e.g., ethylene oxide, units.
Preferred nonionic detergents are those represented by the formula
RO(C2H40)nH
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wherein R is the residue of a linear saturated primary or secondary
alcohol (an alkyl) of 10 to 18 carbon atoms and n is an
integer from 5 to 20 or 5 to 12. The preferred nonionic
- detergents may be referred to as higher fatty alcohol polyoxy-
ethylene ethanols ~the terminal ethanolic part of these ethers
` is included in the number of oxyethylene groups counted in
the mol of the nonionic). Typical commercial nonionic surface
active agents suitable for use in the invention include Neodol
23-6.5, an ethoxylation product with an average of about 6.5
mols of ethylene oxide per mol of a 12 to 13 carbon atom chain
fatty alcohol, Neodol 25-7, a 12 to 15 carbon afom chain fatty
alcohol ethoxylated with an average of 7 of the ethylene oxide
units, Neodol 45-11, which is an ethoxylation product ~having
an average of about 11 ethylene oxide units) of a 14 to 15 carbon
- atom ~average) chain fatty alcohol (all made by Shell Chemical
~ Company) and Alfonic ~ 1618-65, which is a 16 to 18 carbon alkanol
.~ ethoxylated with an average of 10 to 11 ethylene oxide units
(Continental Oil Company). Also useful are the Igepals ~ of
GAF Co., Inc. In the above description higher, as applied
~0 to higher alkyl, higher fatty, etc., means that 8 to 20,
preferably from 10 or 12 to 18 càrbon atoms are present.
The zeolites utilized in the present invention include
the crystalline, amorphous and mixed crystalline-amorphous
zeolites of natural or synthetic origin or mixtures thereof
that will be of satisfactorily quick and sufficiently effective
~ - :
hardness ion counteracting activity. Preferably, such materials
are able to react sufficiently rapidly with a hardness ca~ion,
such as one of calcium, magnesium, iron and the like, to soften
the wash water before adverse reactions of such hardness ions
with fibers of the laundry, any soils thereon and any constituents
of the synthetic organic detergent compositions made according
to the present invention, or any combination thereof. The
.~ useful range of calcium ion exchange capacities is from about
a~ 200 milligram equivalents of calcium carbonate hardness per
gram of aluminosilicate to 400 or more of such milligram
. equivalents (on an anhydrous zeolite basis), per gram. Prefer-
ably such range is about 250 to 350 milligram equivalents per gram.
The water insoluble crystalline aluminosilicates used
are often characterized by having a network of substantially
uniformly sized pores in the range of about 3 to 10 Angstroms,
often being about 4 A (nominal), such size being uniquely deter-
mined by the unit structure of the particular type of zeolite
crystal. Of course, zeolites containing two or more such networks
of different pore sizes can also be satisfactorily employed, as
~0 can be mixtures of such crystalline materials with each other and
with amorphous materials.
The zeolite should be a univalent cation-exchanging
zeolite, i.e., it should be an aluminosilicate of a univalent
cation, such as sodium, potassium, lithium (when practicable) ;
or other alkali metal, ammonium or hydrogen. Preferably the
univalent cation of the zeolite molecular sieve is an alkali
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19
metal cation, especially sodium or potassium, and most prefer-
ably is sodium, but various other cations are also useful.
Crystalline types of zeolites utilizable as molecular
sieves in the invention, at least in part, include zeolites of
the following crystal structure groups: A, X, Y, L, mordenite,
` and erionite, of which types A and X are preferred. Mixtures
;; of such molecular sieve zeolites can also be useful, especially !`.
when type A zeolite is present. These crystalline types Oe
~ zeolites are well known in the art and are more particularly
10 described in the text Zeolite Molecular Sieves, by Donald W.
Breck, published in 1974 by John Wiley ~ Sons. Typical
commercially available zeolites of the aforementioned structural
types are listed in Table 9.6 at pages 747-749 of the Breck
text.
Preferably the zeolite used in the invention is
synthetic and it is most preferable that it be of type A or
similar structure, particularly described at page 133 of the
aforementioned text. Good results have been obtained when a
Type 4A molecular sieve zeolite is employed, wherein the
~0 univalent cation of the zeolite is sodium and the pore size
of the zeolite is about 4 Angstroms. Such zeolite molecular
sieves are described in United States patent 2,882,243, which
refers to them as Zeolite A.
Molecular sieve zeolites can be prepared in either
a dehydrated or calcined form which contains from about O or
about 1.5% to about 3% of moisture or in a hydrated or water
loaded form which contains additional bound water in an
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. amount from about ~ up to about 36% of the zeolite total
weight, depending on the type of zeolite used. The water-
containing or hydrate form of the molecular sieve zeolite is
preferred in the practice of this invention. The manufacture
of such hydrated crystals is well known in the art. For
example, in the preparation of Zeolite A, referred to above,
the hydrated zeolite crystals that are formed in the crystalliza-
tion medium (such as a hydrous amorphous sodium aluminosilicate
gel) are used without the high temperature dehydration
(calcining to 3% or less water content) that is normally " `
practiced in preparing such crystals for use as catalysts,
e.g., cracking catalysts. The crystalline zeolite, in
either completely hydrated or partially hydrated form, can
be recovered by filtering off the crystals from the crystal-
lization medium and drying them in air at ambient or other
suitable temperature so that their water contents are as
desired, usually being in the range of about 5 to 20% moisture,
preferably 15 to 22%. However, because at least partial
hydration may sometimes be effected during manufacture of
the compositions of the present invention, the moisture
content of the molecular sieve zeolite being employed may
sometimes be as low as 0 percent at the start of the process
of manufacturing the present detergent compositions. ~ ;
Preferably the zeolite to be used will be initially
in a finely divided state, with the ultimate particle diameters
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being below 15 microns, e.g., 0.001 to 15 microns, preferably
; being from 0.01 to 10 microns and especially preferably of
- Q.l to 8 microns in mean particle size, e.g., 4 to 8 microns,
if crystalline and 0.01 to 0.1 micron, e.g., 0.01 to 0.05 micron,
if amorphous.
Although the crystalline synthetic zeolites are more
~ common and better known, amorphous zeolites may be employed
instead and are often superior to the crystalline materials in
various important properties, as will be described, as may be
mixed crystalline-amorphous materials and mixtures of the variou,
types of zeolites described. The particle sizes and pore sizes
of such material will usually be like those previously described
but variations from the described ranges may be made, providing
that thQ materials function satisfactorily as builders in the
present compositions and do not objectionably overwhiten dyed
materials with which they are treated in aqueous media. Various
suitable crystalline molecular sieve zeolites are described in
Belgian Patent No. 828,753; in published German Patent
Specification No's P 25 38 679.2; P 26 56 009.8; and P 26 56
251.6; and in British Patent No's; 1,429,143, 1,437,512
1,464,427 1,473,201 and 1,473,571.
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:. The manufacturings of amorphous and mixed amorphous~
crystalline aluminosilicate ion exchanging zeolites are des-
. cribed in British patent~specificatlon No. 1,470,250. A
preferred ion exchangi~ng zeolite~is~the amorphous zeolite of
Belgian:patent 835,351 of the formula
M O Al o (Si2)z wH2O ,
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wherein M is a monovalent cation, preferably an alkali metal,
z is from 1.5 or 2.0 to 3.8 or 4 (2 is sometimes preferable)
and w is from 2.5 to 6, especially when M is sodium. Such
patent and applications are also incorporated herein by
reference to avoid the necessity for lengthy recitations of
such materials, methods for their manufacture and uses, etc.
The formula given above may be varied to
(Na20)x (A12~3)y (SiO2)z w H20
and usually, when x is 1, y will be from 0.8 to 1.2, z will
be from 1~5 to 5 and w will be 0 to 9, such limits preferably
being 0.9 to 1.1, 2.0 to 3.8 and 2.5 to 6 or 3.0 to 4.5 there-
about. The chemical or structural formula will preferably
be the following or approximately of that formula:
~Na2o)6(Al2o3)6(sio2)l2 27 H20
but the mols of water present may be 15 to 27, e.g., 20 or 24
to 27. Note that in such chemical formula the x : y : z : w
ratio is 1 : 1 : 2 : 4.5.
` The alkali metal carbonate employed will desirably
be of particle sizes within the No. 20 to 200 range, United
States Sieve Series ~preferably 100 to 200), but various other
sizes of particles, up to about 8 mesh and as fine as 325
mesh may be used, providing that they dissolve and/or disperse
readily in the aqueous crutcher mix. Solutions may also be
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employed, provided that moisture contents of the crutcher
mix resulting are not thereby raised too high. Normally the
alkali metal (sodium or potassium being preferred) carbonate,
most preferably as the sodium salt, will be essentially
anhydrous in preferred embodiments of the invention but
paEtially hydrated carbonates may also be used. The powdered
; carbonate is readily made into a suitable aqueous slurry
with the zeolite and water, which slurry is easily spray
dried to`particles which readily sorb nonionic detergent,
either alone or mixed with a suitable silicate such as a
water soluble (hydrous) silicate. It is preferred ~hat the
carbonate employed be essentially pure sodium carbonate,
usually over 95% pure, without the presence of bicarbonate which
is in sodium sesquicarbonate, Wegscheider's salt or the
commercial products which are mixtures of carbonates and
bicarbonates, such as Snowlites*, I and II (Allied Chemical
Corporation).
The water of the crutcher mix and of the final product
is preferably deionized water or water which may be present as
~0 the solvent in aqueous solution or dispersion of one or more
of the components of the crutcher mix. The water employed,
if added, will usually have a hardness content of less than
150 p.p.m., preferably less than 50 p.p.m. and more preferably
less than 10 p.p.m., calculated as calcium carbonate. Although
deionized water is preferable, tap waters low in hardness contents
may also be employed. The moisture contents of the products
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are those which are removable by heating to a temperature of
- 105C for five minutes.
The water soluble alkali metal silicate which is
employed is that which is usually referred to as a hydrous alkali
metal silicate, preferably sodium silicate of Na20:SiO~ ratio
in the range of 1:1.5 to 1:2.5, preferably 1:1.8 to 1:2.4,
e.g., 1:2. Although it is possible to add such silicate to the
aqueous crutcher with the carbonate and the zeolite when, in
making the present detergent compositions, such procedure is
followed, objectionable deposits of residues are sometimes noted
on washed fabrics or laundry and because such deposits are to be
avoided and it has been found that they are substantially avoided
by post-addition of hydrous alkali metal silicate, such post-
addition method is normally utilized. In post-addition the
~` hydrous sodium silicate, preferably in particulate or powdered
form, usually with the particle sizes in the 10 to 200 mesh range,
e.g., 10 to 150 mesh, will be admixed with the spray dried base
beads of zeolite and carbonate before spraying onto tumbling
surfaces of such mixture the nonionic detergent in liquid form
for sorption by the spray dried beads and, to some extent, by
the hydrous silicate. Typical hydrous sodium silicate screen
analyses (for Britesils* H20 and H24) follow: 55% through No. 10
sieve and on No. 48; 40% through 48, on 65; 4% through 65, on
100; and 3% through 100 on 150.
In addition to the mentioned components of the final
product, in preferred compositions various adjuvants will also
be favored. For example, to improve cleaning a proteolytic
enzyme or equivalent enzyme may be post-added (normally such
are not included in the crutcher mix because spray drying has
*Trademark - 15 -
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an inactivating effect on such enzymes). The enzymes that may
be employed are generally effective at p~l ranges from about 4
to 12, preferably about 8 to 11. Although the proteolytic
enzymes are subject to some degradation by heat they may be
employed in washing solutions at temperatures up to about 80C
and are also effective at low temperatures, down to about 10C.
Among the proteolytic enzymes that are useful may be mem ioned
pepsin, trypsin, chymotrypsin, bromelain, collagenase, keratinase,
carboxylase, amino peptidase, elastase, subtilisin and
aspergillopepidases A and B. Preferred enzymes are subtilisin
enzymes manufactured and cultivated from special strains of
spore-forming bacteria, particularly Bacillus subtilis.
Proteolytic enzymes such as Alcalase*, Maxazyme*,
Protease AP, Protease ATP 40, Protease ATP 120, Protease L-252
and Protease L-423 are among those enzymes derived from strains
of spore forming bacilli, such as Bacillus subtilis. Different
. :
` proteolytic enzymes have different degrees of effectiveness in
aiding in the removal of stains from textiles and linen.
Particularly preferred as stain removing enzymes are subtilisin
enzymes. Metalloproteases which contain divalent ions such as
calcium, magnesium or zinc bound to their protein chains are of
interest. The manufacture of proteolytic enzyme concentrates
is described in German Offenlegenschrift 1,800,508 and in
Dutch patent application, 6,815,944.
Instead of or in partial replacement of the proteolytic
4 enzyme, other enzymes may also be used, usually for specific
*Trademark - 16 -
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purposes. Thus, an amylase may be employed, e.g., bacterialamylase of the alpha type, such as is obtained by fermentation
of Bacillus subtilis. Among the other enzymes that may be used
are those characterized as hydrolytic, lipolytic, oxidizing,
reducing and glycolytic. Such include catalase, lipase, maltase
and phosphatase. The mentioned enzymes and classes thereof, while
considered to be most useful, are not the only effective ones
in the present products. Virtually any enzymes that contribute to
loosening of the bonds by whic}l soils or stains are held to fibrous
materials may be used in present formulas. Guides to such use
may be found in Principles of Biochemistry by White~ Handler,
Smith and Stetten (1954).
Another preferred component of the present laundry
detergents is a fluorescent brightener. The fluorescent bright-
eners are members of a well-known class in the detergent art
and usually are reaction products of cyanuric chloride and the
disodium salt of diamino stilbene disulfonic acid, benzidine
sulfone disulfonic acid, amino coumarins, diphenyl pyrazoline
derivatives or naphthotriazolyl stilbenes. Such materials are
~0 described in the article Optical Brighteners and Their Evaluations
by Per S. Stensby, a reprint of articles published in
Soap and Chemical Specialties in April, May, July, August and
September, 1967, especially a~ pages 3-5 thereof. Among such
brighteners are Tinopal* 5BM (Geigy), Tinopal* RBS, S~F* (Ciba),
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and one known as Stilbene No. 4, disodium 4,4'-bis-(4-anilino-
6-morpholine-s-triazine-2-ylamino)-2,2'-stilbene disulfonate.
Of these, Tinopal 5BM is generally preferred.
Various other constituents and adjuvants may be
present in the crutcher mix or may be post-added, including
foam improvers, foam depressants, fungicides, antioxidants,
sanitizers, stabilizers, chelating agents, soil suspending
agents, soil anti-redeposition agents, colorants (pigments and
~^ dyes), bleaches and perfumes. Such materials are well-known
; 10 in the art and need not be recited at length here. With
respect to the making of the crutcher mix it is highly
preferred to omit from such mix any surface active or detersive
materials, which tend to produce lower bulk density spray
dried beads.
The proportions of active materials in the final
product should be in the range of 1 : 0.1-1.5 : 0.1-0.3 :
0.2-1.0 for zeolite : carbonate : silicate : nonionic detergent. ;
Preferably, such proportions will be 1 : 0.2-1.0 : 0.15-0.25 :
0.3-0.8, respectively. Percentagewise, such constituents plus
Z0 water are 25 to 70% of synthetic zeolite, 8 to 35% of sodium
carbonate. 5 to 15% of hydrous sodium silicate, 15 to 25% of
nonionic detergent and 2 to 15% of water. Normally 0 to 10% of
adjuvants, e.g., 2 to 7% are also present. Preferably such
percentages will be 30 to 60% of synthetic zeolite, 8 to 30%
; of sodium carbonate, 7 to 12% of hydrous sodium silicate,
17 to 23% of nonionic detergent and 5 to 12% of water. In
a particular
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preferred formulation there will be present about 45% of zeolite,
13% of sodium carbonate, 8.1% of hydrous sodium silicate, 20% of
nonionic detergent, 2% of fluorescent brightener, 1.5% of
proteolytic enzyme, 0.2% of pigment, 0.3% of perfume and 99% of
water. The fluorescent brightener content of these products
will normally be in the range of 0.05 to 3%, preferably 1 to
2.5% and the proteolytic enzyme con~ent, including normally
present carrier for such enzyme, will be from 0.5 to 3%,
preferably 1 to 2%, when present. Various other adjuvants which
may also be employed will normally not total more than 5% and
preferably will be less than 3%, with the percentages of
individual components being less than 1% and preferably 0.5%
or less. Thus, from 0.1 to 0.4% pigment may be present, as
may be 0.1 to 0.4% perfume. If desirable, the percentage of
anti-redeposition agent may be as high as 1% but normally the
percentage thereof, if present, will be from 0.5-2.0%.
In the crutcher mix the percentages of components are
usually 20 to 60% of zeolite, 5 to 30% of carbonate and 25 to
60% of water, possibly with 1 to 5% of adjuvants, too.
~0 The high bulk density particulate heavy duty laundry
detergent product of this invention will usually be in free flow-
ing rounded bead form such as that of other spray dried products,
although the bead interior may be virtually honeycombed. The
particle sizes of the beads will normally be in the range of No's.
~2`
6 to 160 sieve, preferably No's. 8 to lO0 sieve, with less than
10%, preferably less than 5% and more preferably less than 1% of
the product being outside such ranges. The bulk density of the
finished detergent will normally be at least 0.6 g/ml, preferably
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at least 0.65 g/ml and most preferably is in the 0.65 to 0.85
g/ml range, e.g., 0.71 to 0.83 g/ml. The flow rates of such
products are excellent and usually will be greater than 70% of
the rate of free flowing sand of similar particle size, normally
being from 70 to 95% thereof and preferably 75 to 95% thereof.
Although the 0.65 to 0.85 g/ml bulk density range is preferred,
by changing formulas and spray drying techniques it can be changed
upwardly and downwardly, e.g., to 0.5 and 0.9 g/ml.
In the manufacture of the invented laundry detergent it
is important that a sorptive bead be made for absorption of nonionic
detergent thereon. Such sorption should be sufficient so that the
nonionic detergent is passed into the bead interior and therefore
does not tend to cause caking of the beads or poor flow properties.
~hile some forms of sodium carbonate have been found to be good
sorbents for nonionic detergents ~most are not), products made
with the acceptable sorbent alone as the builder, at least in
quantities needed to make compositions of the type whlch are ~-
acceptably detersive tend to have objectionably high pH's. Even so,
such products are not as free flowing as those of the present
invention. For example, Flozan, a sodium carbonate formerly
manufactured by Diamond Shamrock Corp., could absorb 20% of nonionic
detergent but most carbonates were limited to 10%. Still Flozan-
nonionic detergent mixtures were not as free flowine as the ~ -`
invented products. Also because carbonate tends to precip1tate
out calci~n and magnesium and other alkaline earth metal and
heavy metal ions as insoluble compounds it may give rise to
chalkiness in washed materials. Still, when employed in the
- 20 -
relatively small percentages of this invention in a spray dried
product with synthetic zeolite of the type described, although
both components may be considered as separately tending to increase
residue problems on washed fabrics, it is found that when employed
in the proportions described and with hydrous sodium silicate and
nonionic detergent being post-added thereto the residue level is
not objectionable. In other words, when the zeolite and carbonate
are spray dried together in the proportions described, the product,
which includes two materials, each of which may develop residue
problems, is found to be better than would be expected with respect
to residue deposition. Furthermore, the relatively small quantity
of carbonate present reduces the toxicity of the product and
diminishes the likelihood of esophageal burns if the product should
be accidentally ingested by infants or children.
In manufacturing the absorbent, yet comparatively high
bulk density spray dried detergent base beads, the spray drying
operation is conducted in a normal manner, with only zeolite,
carbonate, water and temperature stable adjuvants, such as fluores-
cent brightener and pigment, normally being present. It is possible
to spray dry a limited quantity of silicate, usually no~more than
15% thereof, e.g., 5 to 12%, together with the rest of the crutcher
mix but generally it is preferred to post-add hydrous sodium
silicate instead. If silicate is spray dried with the rest of the
` base composition it will preferably be a sodium silicate of Na20:
SiO2 ratio in the range of 1:2.0 to 1:2.5, e.g., about 1:2.4.
Whether or not the silicate is present in the
crutcher mix such mix will normally include about 40 to 75%
of solids and about 25 to 60% of water. Preferably, the
~` :
:'
_ 21 -
1~43L~1~
. . .
; water content will be about 25 to 50 or 60%, with the balance
: of the mix being non-surface active solids. The crutcher
will usually be provided with heat exchange means so that
the temperature of the mix may be regulated, normally within
the range from room temperature to 90C, preferably 20 to
70C and most preferably about 45 to 65C. Crutching times
are usually in the range of 5 minutes to one hour, preferably
10 minutes to 30 minutes and within this range will desirably
be as short as possible with the obtaining of good mixing. If
any silicate is present in the crutcher mix it will usually
be added as an aqueous solution with the other components,
the carbonate, heat-stable adjuvants and zeolite, with the
zeolite preferably being admixed last, often as a slurry
(some of the water of the crutcher mix being utilized to
form the slurry). If the silicate should thicken the mix
objectionably during crutching it may be subjected to high
shear.
After completion of crutching the cru~cher mix is
atomized, preferably by being forced through a circular
~0 nozzle of internal diameter in the range of about 0.5 to 2
mm, at a pressure of about 10 to 50` kg/sq cm gauge, into
a spray tower, preferably a countercurrent spray tower, in
which the drying air is at a temperature of about 150 to 350C.
The tower may be about 8 to 15 meters high and about 2 to 4
meters in diameter and the product exiting therefrom is of
particle sizes substantially in the 6 to 160 United States
Sieve Series
;
. ' .
.:
- 22 -
,, :.
4~ 9
ran~e and is screened so as to be substantially all within
such range or a narrower range, e.q., 8 to 100. Instead of
high pressure atomization of the particles through an orifice,
spinning disc atomization or equivalent mcthods may be
employed.
After production of base particles, when they
- contain no silicate a particulate solid silicate such as
hydrous sodium silicate, preferably of the type sold by
Philadelphia Quartz Company as Britesil, of 1:2 or 1:2.~
Na2O:SiO2 ratio, is mixed with the base beads in an inclined
drum or other mixing and/or tumbling devicc, normally over a
~` period of about 1 to 5 minutes, and nonionic detergent, in
liquid state and at a temperature in the range of 20 to
70C., preferably 30 to 60C., is sprayed onto the tumbling
surfaces of the base beads, preferably after dry mixiny
thereof with powdered hydrous sodium silicate. The atomized
globules of nonionic detergent may be of any suitable size
" but normally are in the 0.5 to 3 mm. diameter range, preferably
`~ 1 to 2 mr~l. dia. Spray application of the nonionic detergent
~0 to the tumbling particles normally takes place over a period
of from 1 to 20 minutes, preferably from 2 to 10 minutes.
`While the base particles may be heated to temperatures from
30 to 60C. to promote maintenance of normally pasty or
solid nonionic detergent in liquid form this is usually not
~ .
. .
'
- 23
:`
dpne because heating of the detergent suffices to accomplish
this and for the normally liquid detergents no heating is
needed. After completion of addition of the nonionic
. ..
detergent other materials to be post-added, such as proteolytic
- enzyme and perfume, may be applied. It is possible to apply
the proteolytic enzyme and any-other powders first, merely
by mixing it or them with the base particles including
nonionic detergent, normally over a period of l to 10 minutes,
pre~erably from 1 to 5 minutes, and to post-add the perfume
over similar periods of time, preferably as a spray, with
the sprayed globules beiny of sizes like those described for
the nonionic detergent. Particle sizes of the product may
be regulated by controlling the mixing conditions and the
particle sizes of the powders and sprayed droplets but -
usually screening after manufacture will also be employed to
obtain the desired 6 to 160 or 8 to 100 sieve size rangesO
The advantages of the present invention with
respect to product and process have been mentioned but now
will be discussed in further detail. The free-flowing high
bulk density particul~te product lends itself to ready and
convenient use. The packa~e employed may be a "bottle",
~` rather than a large detergent box, which is decidedly less
con~enient. The bottle may be capped and so may be positively
sealed from external moisture, which sometimes causes lumping
~5 of detergents, and may be protected from spilling. Because
.
.
_ _ . .. . . . __ _ _ . . ._ _ . .. . .. .
$9
.
of the higher bulk density, in addition to the packaging
being of morc convenient size and type, the volume of detergent
composition to be utilized is smaller and more readily
measured. Of course, great savings in storage and display
space at point of sale are made. Althou~h in some circumstances
a limited proportion of p~osphate, e.g., up to 10~, may be
intentionally added to the prescnt compositions, preferably in
~ . .
the crutcher mix, it is a feature o~ this invention that
excellent absorption of nonionic detergent and excellent
detergencv, with little or no depositinc~ of residue onto
washed items, is obtained without the use of any phosphate.
Phosphates have generally been considercd to be better
builders than the other known detergent builders and ar~
usually more sorptive of nonionic detergents and other
li~uids. Still, in the present case, the combination of
3eolite and relatively small quantity o~ carbonate behaves
similarly and is especially useful in conjunction with
nonionic detergent, preferably with hydrous sodium silicate
being post-added to the base beads before (but sometimes after,
~0 too) addition of nonionic detergent. T}-e base beads made,
Wit}lOUt any deter~ent or surface active agent being present
in them, are of the desired characteristics for their subsequent
manufacture into a finished detergent composition by post-
snraying of a nonionic organic detergent: onto them. The
~5 relativel~ small quantity of c~rbonate keel)s the alkalinity
~ .
.
.
` ~ 2s
..........
:; of the product low and maintains the pH, at a normal use
concentration of 0.05 to 0.1~ in wash water, e.g., 0.07~,
,
(1/4 cup in a standard 17 gallon washing machine tubful of
water) in the range of about 8.5 to 11, preferably 9 to 10.5.
The mentioned p~ is safer for washing than higher pH's and
is ideal for the action of any enzyme contained in the product
and thereby helps to improve the washing and stain removing
effe-ts of the detergent composition.
The product resulting, of the composition described
and made by the methods mentioned,.is of excellent flow
characteristics and is of a higher density than a comparable
product including bicarbonate, described in the co-filed
:. application previously mentioned. Such may be attributable
to the higher percentage of zeolite prasent but it is surprising
lS t~at a product so hig~ in zeolite content, with addltional
sodi~ carbonate, should not produce unacceptably high
residue deposits on washed Iaundry. Also, in the present
compositions, although it has been taught that appreciable
contents o~ silicates,. whether post-added or co-spray dried
20 ~ with other portions of detergent composition, are likely to
prod~ce zeolite-sil.icate or other residues on washed laundry,
in the present instance it is found that any residues resulting
are generally con~ercially acceptable and are not cause for
; ~ rejèction o~ the product by the consumers.
The various advantages of the product and process
~` are obtainable without extra materials or processing expenses
other than the cost of the molecular sieve zeolite component
,
.
.
~ 2~ _
~` '' " ' , ' , ' ~
.
` and the use of phosphate is avoided. Also, because the detergent
employed is nonionic it is less susceptibla to inter~erence
from water hardness ions and other impurities and therefore
the products are better washing agents under a wider variety
. . .
of conditions, including cold water washin~. Even in high
l~ardness watexs the compositions tend to disperse better any
insoluble carbonates which may be formed. ~i.nally, although
carbonate in waste wash water entering the sewer and passing
into inland waters is a source of carbon, required by living
organisms, it is not nearly as likely to cause eutrophication
of inland waters as is phosphate, in most circumstances, and
accordingly, is more likely to be tolerated therein.
The following examples illustrata but do not limit
the invention. Unless otherwise ind.~catad all parts are by
weight and all tlnper~tureS are i~ C.
.
~` `
; .
.
.
- 27
-
EXAMPLE 1
Percent
* Neodol 23-6.5 (Shell Chemical Company 20.0
** Molecular Sieve Zeolite 4A, crystalline45.0
S ultimate particle size of ~ ~o 8 microns
(Union Carbide Corp.)
Na C0 13.0
2 3
** Hydrous sodium silicate, Britesil, manufactured 8.1
by Philadelphia Quartz Company (Na20:SiO2 =
1:2.4)
Tinopal 5BM fLuorèscent brightener 2.0
Proteolytic enzyme 1.5
Ultramarine Blue pigment 0.2
Perfume 0.3
Water tincluding water of hydration of 9.9
`; zeolite, silicate, etc.j
100~ 0
* condensation product of higher fatty alcohol of an
average of 12 to 13 carbon atoms with about 6.5 mols o
ethylene oxide/mol.
** Anhydrous basis
A free flowing, high bulk density paxticulate detergent
composition is prepared of the above ormula and is of essentially
` qlobular particles, 99% of which are of sizes (usually considered
` as o~ diameters) in the range of 8 to 100 mesh, U.S. Sieve Series.
.
- 28
.
_ _ . ~ . _ . _ ... ... .. .. _ _ .. _ . . .. .... . . .... _ _ ~
The product has a bulk d~nsity of 0.79 g./ml. and flows at a
rate about 91~ of that of dry sa~d of similar particle size,
` ` the standard for comparison. ~t is an excellent heavy duty
synthetic orsanic detergent, useful for both hot and cold
- 5 water washing of both synthetic and natural fiber textiles and it
does not leave ob~ectionable residues on such textiles, such
as may o~ten be observed after washing with other syn hetic
detergent`compositions wherein substantial proportions of
zeolitè insoluble inorganic builder and silicate are employed
together, when employed at concentrations of O.OS to 0.15%, e.g.,
0.07%, in wash water of medium hardness, e.g., 75 to 125 p.p.m.,
as CaC03.
~ he product is made by admixing in a synthetic
detergent or soap crutcher`at a temperature of 60C. (the
lS water is initially heated and heat on the crutcher is maintained
to reach and hold such temperature) zeolite and sodium
` carbonate, plus stable adjuvants, such as pigment and brightener.
The parts by weight e~ployed are 55 of the zeolite (hydrated),
e~ual to 45 parts of anhydrous zeolite, 13 of sodium carbonate,
O.2 of the pigment, 2 of the brightener and 50 of deionized
water ~plus 10 parts water in the zeolite). Alternatively,
city water of low hardness, less than 50 p.p.m., as calcium
carbon~te, is substituted for the deionized water in some cases.
After about 20 minutes of crutching at a temperature o about
60C.` the crutcher mix is spray dried in a conventional
.
,
~` ` '
. __... .. ..... __.. ~ ....... ..... .. ~.. __._. ... . . _ .
countercurrent spray tower, which is about ten meters high
and three meters in diameter, by pumping it at a pressure of
about 25 kg./sq. cm. gauge through an orifice about 1 mm. in
diameter into drying air (at a temperature of about 300C.
S inlet and 110C. outlet) so:-as to produce a product of a moisture
content of about 14% ~removable at 105C. for 5 minutes),
substantially, usually oYer 80~, in the 6 to 160 U.S. Sieve
Series range, which product is cooled to about room temperature
(i~ above that~ and screened so as to be sub~tantially all
~over 99%) within such range. Alternatively, screening is
effected to particle sizes in the narrower 8 to 100 mesh range.
In both instances the base detergent composition beads made are
of a high ~ulk density, about 0.6 g./ml. and are free flowing,
with such ~low bein~ about ~0~ or more of that of comparably
sized dry sand.
With the base beads are blended about 10 parts`o~
. ,.hydrous sodium silicate (8:1 parts of anhydrous silicate) of
; particlè sizes in the 10 to 100 mesh range (to result in the
formula quantity of silicate in the product) and after about
2~ ~àve minutes mixing there are sprayed onto the mixture 20
parts of the Neodol 23-6.5 in liquid state at a temperature
of about 35C. The particles onbo which the Neodol 23-6.5
is sprayed as a liquid mist, with droplet diameters of~abou~
2 mm., are initially at room temperature (about Z5~C.) The
spraying is effected within a period of about 8 minutes, after
which the product is perfumed by spraying and the proteolyti~
,
- 30
.
~ .
~ L6~L~
enzyme powder, of a particle size between 60 and lO0 mesh, is
dusted onto ~he surfaces of tho particles, still in the mixing
drum, each o which procedures takes about three minukes. The
pro~luct is then allowed to cool to 30C. (if at a higher tempera-
ture) to pre~ent 105s of perfume components by evaporation.
The finished produc~, screened to 8 to lO0 meshsize, is of the desired high bulk density and very good flow
characteristics and is "bottled", packed and warehoused so as to
be ready for shipment. When ~ested, it is found to be a
satisfactory heavy duty detergent, useful for washing in
both hot and cold waters, especially so at low concentration~,
- e.g., 0.07~ in wash water, and surprisi~ly, leaves little or
no visible residue of zeolite and/or silicate or other
materials on the washed`fabrics. The proAuct remains free
flowing during storage. It does not cake objectionably nor
does it develop lazy flow characteristics. The pll of a
0.15~ solution thereof in wash water is about 9.8 and that
of a 0.07~ solution is about 9~5, ideal pll's ~or proteolytic
enzymatic action, which assists the detergent composition in
2~ cleaning and removing stains from washed fabrics, whether of
synthetic (nylon, polyester and permanent press natural-
synthètic blends) or natural fabrics ~cottons).
When the silicate is included in the crutcher mix
insteaa of being post-added (a ~0~ solids content aqueous
solution of Na2O:SiO2 ratio of about l:2.~ is used instead
of particulate hydrous silicat~) an additional ive minutes
. .
crutching time is taken to blend the silicate with the rest
of the crutcher mix tit is added to the carbonate and water
before addition of the zeolite and the water content of the
silicate solution is taken into account in computing the amount
of ~ater to be added to the cru~cher). The produc~ obtained
is a good heavy duty detergent of high bulk density and is
sufficiently free flowing to be commercially acceptable but
is not considered to be as good as the product of the previous
example given.
In another varia~ion of the experiment the hydrou~
sodium silicate, in powder form, is admixed with the rest of the
product and at least partially adhered to it after spraying
onto such product of the nonionic de~ergent. The composi~ion
obtained, while acceptable, is not as good as that wherein
lS the particulate hydrous sodium silicate is mixed with the
zeolite first, prior to spraying onto the mix of the nonionic
detergent. Flow properties are not as good, some caking on
storage is noted and some segregation occ~lrs.
Instead of employin~ the inclined drum for mixing
~n* spray applications, when this is replaced by a twin-
shell, V- or Patterson~Kelley-type bl~nder ~quivalent products
are made.
~lthough, as indicated in the earlier portion of
th`is example, it is preferred to post-add the nonionic
~5 ` deter~ent to the b~ads shortly after manufacture and also to
post-add any other components of the product not in the
` spray dried base beads this can also be done aftex agin~ of
.
- 32
.
.
th~.base beads for periods from 20 minutes to several days,
without loss of their absorbing powers. In such cases it may be
desirable to heat tha beads before application of the nonionic
detergent but by proper choice of nonionic detergent type,
with respect to melting point, this is avoidable.
EXAMPL~ 2
When in the processes and products of ~xample 1
the crystalline 7.eolite 4A is replaced by the corresponding
amorphous material, which has an ul~imate par~icle size (diameter)
in the 0.01 to 0.05 micron range or when the "hole" in the
zeolite is increased or decreased, while still being good
for trapping hardness ions, e.g., to 3 to 6 A, the composition
obtained is of essentially the ~ame flow and bulk density
properties as that of the product of Example 1, is an excellent
1~ heavy duty laundry detergent which leaves no re~idue on
washea clothing and sometimes is of even superior properties
with respect to flow and absenca of residue, compared to the
crystalline product. This is also true but to a lesser extent
~` when 50:50 amorphous : crystalline zeolite mixtures ~re employed.
~0 ~cn type X zeolites are employed instead of type A such
effects ar~ also obtainable. Similarly, when type Y zeolites
~re utilized and other equivalents thereto, useful ~roducts
~re obtainable although they are not as good as those including
the type A and/or X zeolites.
The products of this example and of Example 1 are also
usef:l when the silicate is included partially in the crutcher and
partially in the inclined drum mixer, e.g., half in each, prefer-
ably with the first being Na2O:SiO2 of 1:2.4 silicate and the lat-
ter ~einy hydrous sodium silicate of 1:2 ratio. Altern~tively~ al-
- 33 - .
.
.
though not preferably, the silicate and adjuvants may be omltted,
In addition to varying the type o zeolite present
the types of silicates and-nonionic dcter-~cnt may be changed,
as may be those of the various adjuvants Thus, in the
e~p~riment of ~xample 1, instead of employing the hydrous
silicate of Na20:SiO2 ratio of 1:2, such ratio may be 1:1.8
or 1:2.2 and the product~ ob~ained are s~ill like ~hose
previously described. Instead of utilizin~ Neodol 23-6.5,
~eodol 25-7 and Neodol 45-11 and equally proportioned 2- and
3-component mixtures of such materials are employed. Instead
of Tinopal 5BM, others of the previously mentioned fluorescent
brighteners may be substituted or the brightener may be
omitted entirely. In the latter case the product obtained
is of essentially the same detersive and physical properties,
althou~h desirable brightening of laundry is noticeabl~f
diminished in the ~bsence of the fluorescent compound. In
other variations of the procedure and products of Example 1
the proteolytic enzyme and the Ultramarine Bluc are omitted
from the formula. Alternatively, the colorant is employed
in larger proportion to color somc product particles while
others are uncolored and beads o both types are mixed to
produce a ~peckled version.
In addition to the v~rious components listed
others are also included, e.~., inert filler, such as sodium
~5 sulfate, anti-redeposition agents, such as sodium carboxymethyl
cellulose, antibacterial a~ents, such as tetrabromosalicylanilide,
;` ~ ' . .
~ 3~ _
,_ _ .. _ .. . _ ........ . .. . .. _. . _ __, _ __. . _ . .. .. . .... _ .. .
.
;19
laundry sweetening ~and building salts), such as borax and bleaching mate-
rials, such as sodium perborate. The stable materials are usually yreferably
added in the crutcher whereas the others are post-added, either before or
after spray-on of the nonionic detergent. When such materials are present in
the described compositions, for example, 5% of borax, 5~ of sodium sulfate,
0.5% of sodium carboxymethyl cellulose, 0.1% of antibacterial compound and
10% of sodium perborate, the product formula will be modified accordingly,
preferably by proportional diminutions of zeolite, carbonate and silicate
contents.
In place of the sodium salts of the various mentioned components
corresponding potassium or other suitable soluble salts, preferably alkali
metal salts, are substituted, either in whole or in part, providing that the
characteristics of the products obtained are acceptable and within the ranges
given.
EXAMPLE 3
A crutcher formula is made by admixing 47 parts of sodium aluminum
silicate (molecular sieve type LMS-9611, obtained from Union Carbide Corp.),
9.5 parts of light soda ash, 1.7 parts of Tinopal 5BM Conc., 0.2 part of
Ultramarine Blue pigment and 41.6 parts of water so that the crutcher mix is
~0 of ~8% solids content. The zeolite measurement given is the weight of hy-
`~ drated zeolite added (otherwise in this specification and in the claims an-
hydrous weights are used). Wet and dry remix are also added tq.s.) in such
proportions as to maintain the 48% solids content. The crutcher mix is dried
~s clescribed in Example 1 and a yield of 56.4 parts results, with a moisture
loss of 43.6 parts. 67.1 parts of product are mixed with 10.0 parts of
Britesil H-20 (hydrous sodium silicate, on an "as is" basis) and 0.3 part of
sodium carboxymethyl cellulose (90% active) and 20.0 parts of Neodol 23-6.5
are sprayed onto the moving mixture, in the manner described in Example 1,
; after which the product is perfumed and 1.5 parts of alkaline protease are
dusted onto it. The proteolytic enzyme and sodium CMC are of the particle
_ 35 -
~; :
:
sizes previously described for the enzyme and the Britesil H-20 is of the
sieve analysis previously given. The nonionic detergent is at 35 C and the
beads onto which it is sprayed are at room temperature (25C). The product
resulting contains 44.1% (anhydrous basis) of the zeolite, 11.3% of sodium
carbonate, 2% of Tinopal 5BM Conc., 0.2% of Ultramarine Blue, 1.5% of proteo-
lytic enzyme, 20.0% of the nonionic detergent, 8.1% of silicate solids, 1.0%
of sodium CMC active ingredient, 0.3% of perfume and 11.5% of moisture (in-
cluding moisture in the zeolite and hydrous sodium silicate). The cup weight
is 185 grams per 240 ml and flowability is greater than 70% of that of simil-
arly sized sand. As with the products of the previous examples, it is a goodheavy duty laundry detergent which does not leave white deposits on washed
laundry to an objectionable extent.
EXAMPLE 4
Percent
Neodol 23-6.5 19.2
Type 4A zeolite (hydrated, but anhyd. basis) 45.2
Na2C3 12.8
llydrous sodium silicate (anhydrous basis) 8.6
Fluorescent brightener 2.0
Proteolytic enzyme 1.3
Pigment 0.2
~loisture 10.7
100 . O
The above product is made by the method previously described for
Examples 1-3. The product resulting has a cup weight of 182 g and a flow
wllicll corresponds to 91% of that of similarly sized sand. The particle sizes
are like those of the products previously mentioned. It is a useful deter-
gent and is superior to a commercially successful detergent when tested for
cleaning power against mixed solils on a plurality of fabrics. After washing
soiled laundry with it none to light residue is observable on dark colored
clothing to a careful observer and such is considered to be commercially
;
- 36 -
,
, ,, : : . .
acceptable. The product ages well and passes various other tests for non-
caking, appearance, stain removal, etc.
EXA~PLE 5
The compositions of the products of the previous examples are
varied +10%, +20% and +30%, within the ranges given and similarly, the pro-
cedures are varied with respect to times and temperatures. The products made
are within the desired ranges for flow characteristics, bulk density and par-
ticle size and are of satisfactory heavy duty laundry detersive properties.
For example, the moisture content of the finished product is varied to 5%, 6%
and 10% and all of the products are of acceptable flow characteristics. The
nonionic detergent content is increased to as much as 25% with various form-
l~las withill tlle invention and the silicate content is increased to 15% and,
with proper selection of the formula to produce the most free flowing prod-
r~ uct, to as high as 20% and even, sometimes, 25%. Of course, in all sucn in-
stances wherein the formulas are varied, both with respect to components and
with respect to proportions, care will be taken by one of skill in the art so
as to make a product of desired properties by means of a commercially practic-
able method.
The invention has been described with respect to illustrative ex-
~0 amples and descriptions thereof but is not to be limited to these because itis evident that one of skill in the art, with the present specification be-
fore him, will be able to utili~e substitutes and equivalents and make var-
ious modifications within the scope of the invention.
- 37 -
